The present invention relates to soft feel coatings suitable for coating multi-filament woven fabric and products comprising fabrics coated with soft-feel coatings as well as methods of producing such products.
Soft feel woven-coated fabrics are suitable for use in applications such as clothing textiles, furniture textiles, pool covers, banners and billboard fabrics, rental tent fabrics, truck tarps, cargo container covers and water tank or reservoir covers. Desirable properties include, pleasing tactile finish, good adhesion between the coating and fabric, strength, durability, flexibility, chemical and temperature resistance and recyclability.
Prior soft feel woven-coated fabrics comprised poly vinyl chloride (PVC) coated fabrics. As landfill sites are becoming less common, there is a greater tendency to dispose of articles that contain PVC through incineration. The incineration of PVC can produce hydrochloric acid. It is feared that the hydrochloric acid enters the atmosphere and produces acid rain. It also is feared that dioxins and furans are liberated when PVC is burned at municipal incinerators. Discussions are underway in many nations to ban PVC because of its potentially harmful effect on the environment.
In addition to its environmental problems, flexible PVC-containing articles also pose the problem of having a low molecular weight plasticizer migrate to the surface of the PVC layer. The PVC layer typically contains a low molecular weight plasticizer to impart flexibility to the layer over a wide range of temperatures. This plasticizer is fairly mobile in the PVC layer and usually migrates out of the article, leaving it with a semi-tacky outer surface onto which dirt and other particles can adhere. The migration of the plasticizer also can cause the PVC article to be less flexible, it can allow the plasticizer to enter other articles that are adjacent to the PVC article, and it can interfere with the application of ink on the surface of the article. Further, the most common plasticizer for flexible PVC is carcinogenic to laboratory animals, although a direct link to humans has not been proved. Although high molecular weight plasticizers may be used, which do not migrate out from the interior of the PVC layer, these plasticizers do not impart good flex crack resistance to the PVC-containing article.
Articles are known which comprise fabrics secured to polymeric layers that contain polymers other than PVC. Examples of such articles have been disclosed in the following documents: U.S. Pat. Nos. 4,844,958, 4,636,427, 4,531,994, 4,471,018, 4,351,876, 3,125,462, and 2,299,807. However, none of these patents disclose that such products have good flex-crack resistance so as to be a suitable alternative for a plasticized, PVC-containing article.
Roll-up signs are well known in the outdoor display and traffic control materials art. These signs are portable and can be folded or rolled up for transport and storage until being used again in a non-rolled up or extended condition. Examples of roll-up signs are shown in U.S. Pat. Nos. 5,175,646, 5,016,372, 4,999,938, 4,980,984, 4,694,601, 4,592,158, and 4,490,934. The signs typically comprise a reflective layer having an indicia on the front side and a PVC coated fabric on the back side. In U.S. Pat. No. 5,016,372, a roll-up sign is disclosed that is made of polyethylene plastic.
Other approaches to eliminate PVC include use of polyolefins that are selected for being recyclable and nonpolluting. The polyolefins include, low-density polyethylene, high-density polyethylene linear low-density polyethylene, polypropylene homopolymer, and copolymers of such polyolefins. Polyolefins may be used for both the coating materials and for woven fabric. Particularly preferred for the woven fabric are polypropylene homopolymer and copolymers. Polypropylene has the advantages of flexibility, light weight, low cost and stain resistance. Polypropylene has the disadvantage of poor adhesion to many coating materials.
Of the hundreds of potential polyolefin coatings, very few have produce soft feel products with flexibility and good adhesion to polyolefin woven fabrics. Polyolefin elastomers offer a reasonable chance of success for a desired coating. Traditional polyolefin elastomers include ethylene elastomers such as ADVANTECH® brand elastomer from DuPont, ENGAGE® brand elastomers from Dupont Dow elastomers, and FLEXOMER® brand elastomers from Union Carbide.
An alternate to polyolefin elastomer is SANTOPRENE® brand bondable thermoplastic vulcanizate (TPV). SANTOPRENE® is available in many grades from Advanced Elastomer Systems (AES) of Akron, Ohio. SANTOPRENE® is described as fully dynamically vulcanized EPDM rubber particles in a thermoplastic matrix of polypropylene.
Difficulties are encountered in using elastomer or thermoplastic vulcanizates as fabric coating. Such coatings are often of low abrasion resistance, low adhesion or sticky or tacky. Further such coatings are unable to attain the desired soft tactile characteristic of the present invention.
Accordingly, it is a general object of the present invention to provide a soft tactile coating for polyolefin fabrics with superior tactile, abrasion resistance, flexibility and adhesion characteristics. Another object of the present invention is to provide a soft tactile woven polyolefin fabric of recyclable materials utilizing such coatings.